6639897 has 8 divisors (see below), whose sum is σ = 9658080. Its totient is φ = 4024160.

The previous prime is 6639889. The next prime is 6639907. The reversal of 6639897 is 7989366.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6639897 - 2³ = 6639889 is a prime.

6639897 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6639817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100572 + ... + 100637.

It is an arithmetic number, because the mean of its divisors is an integer number (1207260).

Almost surely, 2^6639897 is an apocalyptic number.

It is an amenable number.

6639897 is a deficient number, since it is larger than the sum of its proper divisors (3018183).

6639897 is a wasteful number, since it uses less digits than its factorization.

6639897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201223.

The product of its digits is 489888, while the sum is 48.

The square root of 6639897 is about 2576.7997593915. The cubic root of 6639897 is about 187.9549556336.

The spelling of 6639897 in words is "six million, six hundred thirty-nine thousand, eight hundred ninety-seven".